This invention relates in general to heat-sealable containers and, more particularly, to glass containers for biological materials which can be hermetically sealed with infrared radiation.
The storage of biological materials in glass containers presents special problems because of the danger of the escape of contagious biological materials, i.e., bacteria and viruses, as well as the danger that continued exposure to air will have a harmful effect on the biological material. For these reasons, it is desirable to form an airtight seal on such containers. Heat-sealing of these containers has been found to be a suitable procedure for forming an hermetic seal only in the limited instances where the high temperatures associated with heat-sealing do not damage the biological material.
These containers have been made of types of glass which are resistant to attack by biological materials and do not contaminate the biological materials. Heretofore, the only glasses known to have the necessary compatibility with biological materials had relatively high melting points. Consequently, in heat-sealing such glass containers, it was necessary to heat the container to a high temperature with, for example, a glass blower's burner in order to melt closed the open end of the container. In most cases where the biological material is to be stored only temporarily before being tested, the conventional heat-sealing process is unsatisfactory because the high temperatures needed to seal the container often damage or result in the destruction of the biological material. Another disadvantage of this procedure is the need for skilled personnel to ensure that the container is completely closed to form an airtight seal. It is desired to have a heat-sealable glass container for biological samples which can be hermetically sealed without deleteriously affecting the biological materials therein. Heretofore, infrared-absorbing glass had not been employed to store biological samples due to its higher cost and its tendency to interact with and/or contaminate the biological material.